Ray,
What's your current rate?
You can submit your OCS/Commissioning package at any time. Being squared away is important. My suggestions in addition to the above:
1. Do volunteer work - tutoring, through a church, wherever.
2. GETTING YOUR PIN IS WAAAAY IMPORTANT!! (Aptly stated above!)
3. Work Hard, be on time, etc.
4. Talk to your Career Counselor - when I applied, successfully, for BOOST several years ago, our NC1 was very helpful in ensuring I had good officer reviews, was in contact w/ the CO, CMC and XO regarding what I wanted, etc.
5. As far as your timeframe, you can apply whenever, but I think you'll need your CO's recommendation - I know I had to have one for both my BOOST & OCS packages.
I think that's all for now!
Good Luck!
Robin